RESUMO
Influenza B viruses (IBVs) are causing an increasing burden of morbidity and mortality, yet the prevalence of culture-adapted mutations in human seasonal IBVs are unclear. We collected 368 clinical samples from patients with influenza-like illness in Missouri during the 2019-2020 influenza season and recovered 146 influenza isolates including 38 IBV isolates. Of MDCK-CCL34, MDCK-Siat1, and humanized MDCK (hCK), hCK showed the highest virus recovery efficiency. All Missourian IBVs belonged to the Victoria V1A.3 lineage, all of which contained a three-amino acid deletion on the HA protein and were antigenically distant from the Victoria lineage IBV vaccine strain used during that season. By comparing genomic sequences of these IBVs in 31 paired samples, eight cell-adapted nonsynonymous mutations were identified, with the majority in the RNA polymerase. Analyses of IBV clinical sample-isolate pairs from public databases further showed that cell- and egg-adapted mutations occurred more widely in viral proteins, including the receptor and antibody binding sites on HA. Our study suggests that hCK is an effective platform for IBV isolation and that culture-adapted mutations may occur during IBV isolation. As culture-adapted mutations may affect subsequent virus studies and vaccine development, the knowledge from this study may help optimize strategies for influenza surveillance, vaccine strain selection, and vaccine development.
Assuntos
Adaptação Fisiológica/genética , Variação Antigênica , Glicoproteínas de Hemaglutininação de Vírus da Influenza/genética , Vírus da Influenza B/genética , Mutação , Estações do Ano , Deriva e Deslocamento Antigênicos , Linhagem Celular , Genoma Viral , Humanos , Vírus da Influenza B/classificação , Influenza Humana/virologia , Missouri , Filogenia , Vírus Reordenados/genética , Desenvolvimento de VacinasRESUMO
A hemodialysis patient with hepatitis C virus infection developed painful blisters on her hands that burst spontaneously. She was found to have serum porphyrin levels >2000 nmol/L. A punch biopsy revealed subepidermal blistering with festooning of dermal papillae associated with a mixed inflammatory infiltrate. Based on the clinical, biochemical, and histologic findings, a diagnosis of porphyria cutanea tarda was made. Treatment was started with twice-weekly phlebotomy and oral hydroxychloroquine and significant clinical improvement resulted.
Assuntos
Hepatite C/complicações , Falência Renal Crônica/complicações , Porfiria Cutânea Tardia/complicações , Diálise Renal , Inibidores Enzimáticos/administração & dosagem , Feminino , Humanos , Hidroxicloroquina/administração & dosagem , Falência Renal Crônica/terapia , Pessoa de Meia-Idade , Flebotomia , Porfiria Cutânea Tardia/tratamento farmacológicoRESUMO
Nebulized epinephrine does not improve clinical status or reduce the length of the hospital stay in infants aged <1 year with acute bronchiolitis. It also does not reduce clinical scores during or shortly after medication administration. In this study, infants requiring oxygen and intravenous fluids-presumably the sickest infants in the study-required longer hospital stays if they received epinephrine. A wheezing infant may be presenting with a first episode of asthma, so a trial of bronchodilators would seem reasonable; however, it appears that the primary intervention for bronchiolitis is supportive treatment, with supplemental oxygen, intravenous fluids, and ventilatory support when needed.